. >> neil: we are waiting for two press conferences, including one about the explosion in tax that killed 16 people and 160 injured. an explosion that governor rick perry described as a nightmare scenario. we'll hear from doctors on the scene, and legal experts on the scene. one behind the investigation, the other behind just how much damage it has caused, and how those injured are faring. to catherine to what people in washington are staying about what's going on in boston or what we might or might not hear out of fbi officials shortly. catherine? >> today we heard from both the secretary of homeland security, janet napolitano, and attorney general eric holder. neither provided details on the case except to say every federal resource available is being given to boston as it is requested. we have new information on the kind of evidence being analyzed. have two tracks of the video and the still images but fox news is told there's a third track having to do with social media. basically a one-mile radius was put of the attack site 24 hours before and 24 hours afterward, and all the social me